1. Field of the Invention
This invention relates to an actuator used, for example, for a cruise control device for automatically controlling running speed of the motor vehicle in the predetermined and desired value.
2. Description of the Prior Art
As an actuator for the cruise control device, a device has been known, which is provided with an output pulley connected to the throttle valve of the engine through a throttle cable, an electric motor, and an electromagnetic clutch for connecting the output pulley and the electric motor by excitation, and so structured as to pull the throttle cable and control the throttle valve in the opening or closing direction by actuating the electromagnetic clutch and rotating the electric motor together with the output pulley.
However, in the aforementioned conventional actuator, the electromagnetic clutch is provided with a clutch yoke and a bobbin formed with a coil, and the bobbin is housed in the clutch yoke by securing the bobbin to the clutch yoke through caulking. Accordingly, there is a problem in that it is troublesome to attach the bobbin into the motor yoke and difficult to save manpower required for assembling the actuator.
Furthermore, in the aforementioned actuator, although a non-magnetic clutch washer is disposed between the clutch yoke of the electromagnetic clutch and a rotor combined with a wheel gear transmitted with rotational force of the electric motor in order to prevent sliding resistance to increase by magnetic attractive force, the clutch washer does not positioned on a side of neither the clutch yoke nor the rotor. Consequently, there is another problem in that it is difficult to accurately incorporate the clutch washer and there is the possibility that the clutch washer is dislocated.